Appeal No. 95-5092
Application 08/032,581
less than the presently claimed lower limit of 0.5 (50%). Furthermore, at Col. 6, lines 36 et
seq., Aldrich teaches that the logical step in order to avoid an excess of sludge would be to
eliminate the iron from the treatment process, but in such cases, undesir-able H S gas
2
would be produced. Therefore, Aldrich teaches that using limited ferrous ion dosages of
10-20% would inhibit the production of H S gas as well as produce a 60 to 70% reduction
2
in sludge.
Accordingly, taking into consideration the entirety of the Aldrich disclosure, we fail
to find any teaching or suggestion or motivation for one of ordinary skill in the art to perform
the Aldrich process by using the claimed amounts of ferrous ion. While the examiner
states at page 4 of the final rejection that the claimed ratio of ferrous ions "would have
been an obvious matter of process optimization to one skilled in the art", it has been
generally held that it is not a matter of prima facie obviousness for one of ordinary skill in
the art to optimize a value outside the operable range disclosed by the prior art. In re
Sebek, 465 F.2d 904, 907, 175 USPQ 93, 95 (CCPA 1972).
The examiner also states at page 4 of the answer that "[a]ppellants have not
presented sufficient factual comparative evidence to show that these amounts are required
for the successful reduction of hexavalent chromium to trivalent chromium and the
precipitation of trivalent chromium at the pH range recited in the instant claims."
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